As a conventional cruise controller for a saddle-seat vehicle is known the one taught by Patent Reference 1. The proposed controller is configured to initiate cruise control when the operator operates a speed set switch upon reaching a desired vehicle speed and to enable the cruise control to be temporarily suspended simply by returning the throttle grip (accelerator) in the close direction. In other words, the configuration is such that, in addition to the cruise control being disabled by brake operation and clutch operation, the cruise control is temporarily suspended by returning the throttle grip in the close direction and is restored by again turning the throttle grip in the open direction, thereby facilitating use of engine braking by speed reduction.
Patent Reference 1: Japanese Published Utility Model Application No. 64-5616
However, for non-saddle-seat vehicles, i.e., four-wheeled automobiles, a broad range of so-called Drive-By-Wire throttle control systems have been proposed in which mechanical interconnection between the accelerator (accelerator pedal) located on the floor at the vehicle operator's seat and the throttle valve is disabled, an electric motor or other such actuator is connected to the throttle valve, the accelerator opening (amount of accelerator depression) is detected, and the throttle valve opening is controlled in accordance with the detected accelerator opening and the like to obtain a preset desired throttle valve opening, thereby performing throttle valve control for improving emissions performance and/or fuel-economy.